Seoul National University's College of Engineering announced on the 15th that a research team led by Professor Yoo Ho-bin of the Department of Materials Science, in collaboration with Professor Son Young-woo from the Graduate School of Convergence Science and Technology and Professor Park Chang-won from Ewha Womans University, has developed a platform for designing new quantum materials by intricately stacking patterns known as 'moire'. The research results were published that day in the international academic journal Nature.
Moire, derived from the French term meaning 'wave pattern', refers to the phenomenon that occurs when two identical lines or shapes are overlaid and moved, creating a wave pattern due to light interference. This is similar to the rippling patterns observed when two mosquito nets are layered or when looking at a thin hanbok. A new lattice pattern may also be seen on a striped shirt in a TV screen.
The scientific community is developing materials that fundamentally change the movement and properties of electrons by applying the moire phenomenon. When two very thin two-dimensional materials, composed of a single layer of atoms like graphene, which consists of carbon atoms arranged in a hexagonal consolidation, are stacked and slightly twisted, a new lattice structure is formed. This allows for precise control of the flow and properties of electrons, accelerating the development of quantum technology and next-generation electronic devices.
In this study, the research team implemented a double moire structure by stacking three layers of graphene and precisely adjusting the twisting angles of each layer, allowing two moire lattices to overlap. Observations under a microscope revealed the formation of unprecedented new lattice patterns, such as triangles, hexastars, and kagome. Kagome refers to a lattice structure where equilateral triangles and hexagons intersect.
Based on experimental results and computer simulations, the research team completed a 'domain lattice state diagram' that outlines which lattice patterns appear depending on the twisting angles. This is expected to serve as guidance for designing materials that can control the flow of electrons more precisely by leveraging the double moire structure.
Professor Yoo Ho-bin noted, "We have experimentally proven that the moire structure can serve as a new tool that goes beyond simple visual effects or geometric arrangements to precisely design interactions between atoms and electron states," and added, "In the future, it will be possible to actively regulate these lattice structures and electron states according to external stimuli such as electric fields."
References
Nature (2025), DOI: https://doi.org/10.1038/s41586-025-08932-0